KR20170137904A - Blends of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) and their uses - Google Patents

Abstract

The present invention relates to a process for the preparation of an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC), an aqueous slurry comprising said blend, and also an aqueous slurry Blends, and their use in paper, paper coatings, foil paper, digital photographic paper, paints, coatings, adhesives, plastics, wastewater treatment or waste water treatment agents.

Description

Blends of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) and their uses

The present invention relates to a process for the preparation of an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC), an aqueous slurry comprising said blend, and also an aqueous slurry Blends, and their use in paper, paper coatings, foil paper, digital photographic paper, paints, coatings, adhesives, plastics, wastewater treatment or waste water treatment agents.

The quenching effect can be realized by a different means that provides a fine illuminance of the surface of the paint or coating film that is scattered in such a way that the incident light induces the quenched surface. Physics is known to support this. A condition that achieves a fully extinct effect without resorting to full light absorption is to scatter incoming light away from the square. This means diffracting direct light that irradiates the substrate to induce scattering diffusion.

A variety of quenchers are known in the paint and coating industry and are mixed with the paint and coatings, such as silica, waxes, organic materials and even fillers being added to form fine roughened surfaces after the paint or coating drying process. It is generally recognized that the greater the amount of the quencher in the paint or coating, the stronger quenching effect. In contrast, products with larger particle size are more powerful for quenching efficacy, but the resulting paint or coating film surface is not so smooth. A quencher having a smaller average particle size distribution does not provide a sufficient quenching effect, but provides a smoother paint or coating surface.

Japanese Patent Application JP-A-2003 147275 discloses a coating material composition comprising a binder component and phosphoric acid treated calcium carbonate. The coating material provides a quenching surface, i.e. the treated calcium carbonate has an average particle size of less than 10 μm, a BET specific surface area of 70-100 m ² / g, and an oil absorption of 130-20 ml / 100 g.

WO 2006/105189 A1 relates to a composition comprising agglomerated calcium carbonate and to agglomerated particulate minerals. The dry agglomerated calcium carbonate beads have a weight median total particle size (d ₅₀ ) of at least 5 μm, even greater than 100 μm. The agglomerated calcium carbonate beads are made of paper, paint, coating or ceramic.

US 5,634,968 relates to carbonate-containing mineral fillers, and more particularly for use as quenchers. The mineral material is natural and / or precipitated calcium carbonate having a d ₅₀ of 9.6-20.5 μm, and heavy natural calcium carbonate is preferred.

US 5,531,821 and US 5,584,923 disclose and claim acid-resistant calcium carbonate prepared by mixing calcium carbonate with anionic and cationic salts. The acid-resistant calcium carbonate is used in a neutral to slightly acidic papermaking process.

US 6,666, 953 discloses pigment fillers containing natural carbonates treated with at least one provider of medium to high H ₃ O ⁺ ions and gaseous CO ₂ .

US 2008/0022901 discloses a process for the production of calcium carbonate and the reaction product (s) of one or more heavy- to heavy-H ₃ O ⁺ ion donors with the carbonate and the reaction product of the gaseous CO ₂ and calcium carbonate produced in situ and / ) And a dry product formed in situ by multiple reactions between one or more compounds of the formula RX.

EP 2 264 109 A1 and EP 2 264 108 A1 disclose a process for preparing surface-reacted calcium carbonate and its uses and also to a process for the production of surface-reacted calcium carbonate, the resulting products and their uses, which carry out the weak acidification.

EP 2 684 916 A1 discloses spherical spherical surface modified spherical calcium carbonate-containing mineral particles having an average particle diameter of more than 1 탆, and uses thereof.

WO 2004/083316 A1 describes a process for the production of a reaction product (water) of calcium carbonate and at least one heavy H ₃ O ⁺ ion donor and the carbonate salt used in the paper field, such as quenching and / or paper coating, from one gaseous CO ₂ and the reaction product of the carbonate (s), and at least one aluminum silicate and / or at least one synthetic silica and / or at least one calcium silicate and / or one or at least one silicate salt, such as sodium silicate and / or By double and / or multiple reactions between potassium silicate and / or potassium silicate and / or lithium silicate, preferably sodium silicate and / or at least one aluminum hydroxide and / or at least one sodium aluminate and / or potassium aluminate And to mineral-pigment-containing products formed.

However, the manufacture of known quenchers generally involves a combination of low productivity and high energy consumption for material drying, thus consuming considerable energy and cost. As a result, such quenching agents are usually obtained in the form of an aqueous suspension comprising a relatively large amount of water. More specifically, the solids content of the aqueous suspension comprising the material is typically less than 10% by weight based on the total weight of the aqueous suspension.

Accordingly, there is a continuing need for an alternative process that produces a quencher in the form of an aqueous suspension having a high solids content, and that provides higher productivity and lower energy consumption for drying, especially for processes that are less energy and less expensive. In addition, it is desirable to produce a quencher that provides a performance equal to, or even better than, conventional quencher at sufficient quench performance, especially at lower cost.

Accordingly, it is an object of the present invention to provide a process for preparing a quencher in the form of an aqueous suspension. It is a further object of the present invention to provide a process for preparing a quencher in the form of an aqueous suspension having a high solids content. It is a further object of the present invention to provide a method of making a quencher in the form of an aqueous suspension which provides high productivity and low energy consumption for drying, so that energy and cost are less consumed. A further object is to provide a quencher that provides the same or even better performance as an existing quencher with sufficient quenching performance, especially at a lower cost.

These and other objects are solved by a process for producing an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC). The process

a) providing an aqueous slurry of surface modified calcium carbonate containing particles (MCC)

b) providing an aqueous slurry of precipitated calcium carbonate containing particles (PCC)

c) The aqueous slurry of said surface modified calcium carbonate containing particles (MCC) of step a) to obtain an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) With an aqueous slurry of the precipitated calcium carbonate-containing particles (PCC) of step b), and

d) dewatering the aqueous slurry obtained in step c) to obtain an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC)

Wherein the blend comprises surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a weight ratio [MCC / PCC] of 99: 1 to 50:50.

The inventors have surprisingly found that this process of preparing an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) can produce an aqueous suspension having a high solids content Respectively. It has further been observed that the process provides higher productivity and lower energy consumption for drying to lessen energy and cost. Furthermore, the inventors have found that the process produces quenchers with sufficient quenching performance, in particular quenchers that provide the same or even better performance than existing quenchers.

Advantageous embodiments of the invention are defined in the corresponding subclaims.

According to one embodiment, the surface modified calcium carbonate containing particles (MCC) in the aqueous slurry of step a) is a substantially spherical surface modified calcium carbonate containing particle (bMCC).

According to another embodiment, the surface-modified calcium carbonate-containing particles (MCC) in the aqueous slurry of step a) have a mean grain diameter d ₅₀ of 4 μm-100 μm as measured by a Malvern Mastersizer , Preferably from 5 [mu] m to 75 [mu] m, more preferably from 10 [mu] m to 55 [mu] m and even more preferably from 15 [mu] m to about 35 [mu] m and / or b) the BET specific surface area measured using nitrogen and BET method ≥ 15 m ² / g, preferably ^{20 m 2 / g-200 m} 2 / g, more preferably ^{30 m 2 / g-150 m} 2 / g, still more preferably 40 m ² / g-100 m ² / g and / or c) the particle size distribution d ₉₈ / d ₅₀ is in the range of <3, more preferably ≤ 2.9, and preferably in the range of 1.4-2.9.

According to another embodiment, the aqueous slurry of surface modified calcium carbonate containing particles (MCC) of step a) is present in an amount of up to 8% by weight, preferably of from 0.01% to 5% by weight, based on the total dry weight of the aqueous slurry %, More preferably 0.05 wt% -4 wt%, and even more preferably 0.2 wt% -3 wt%.

According to one embodiment, the at least one treating agent is selected from the group consisting of ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, aluminum sulfate, aluminum chloride, and / or its hydrated forms, silicates, A water-soluble amphoteric polymer, a water-soluble nonionic polymer, and combinations thereof.

According to another embodiment, the precipitated calcium carbonate-containing particles (PCC) in the aqueous slurry of step b) have a mean grain diameter d ₅₀ , as measured by a sedimentation method, of 0.1-100 μm, preferably 0.25-50 μm, More preferably 0.3-5 μm and most preferably 0.4-3 μm and / or b) the BET specific surface area measured using nitrogen and BET method is 1-100 m ² / g, preferably 2-70 m ² / g, more preferably 3-50 m ² / g, or especially 4-30 m range of ² / g and /, c) a particle size distribution d ₉₈ / d ₅₀ is ≥ 3, more preferably ≥ 3.2 , Preferably in the range of 3.2-4.5.

According to another embodiment, the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC) of step a) and / or the precipitated calcium carbonate-containing particles (PCC) of step b) Having a solids content of at least 5% by weight, preferably from 5 to 60% by weight, more preferably from 10 to 35% by weight, most preferably from 15 to 30% by weight, ) Has a solids content of at least 5% by weight, preferably 5-40% by weight, more preferably 10-35% by weight, most preferably 15-30% by weight, based on the total weight of the aqueous slurry / Or c) obtained in step d) is at least 15% by weight, preferably 15-50% by weight, more preferably 20-45% by weight, most preferably 20-40% by weight, based on the total weight of the aqueous slurry Has a solids content of% by weight.

According to one embodiment, the blend comprises a) a surface modified calcium carbonate containing particle (MCC) having a weight ratio [MCC / PCC] of from 95: 5 to 65:35, preferably from 90:10 to 70:30 and precipitated calcium carbonate (PCC), and / or b) a median grain diameter d _{50 as} measured by the sedimentation method of from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, Preferably 20 μm to 35 μm, and / or c) a BET specific surface area of ≧ 5 m ² / g, preferably 10 m ² / g-200 m ² / g measured using nitrogen and BET method , more preferably from ^{20 m 2 / g-150 m} 2 / g, still more preferably ^{30 m 2 / g-100 m} 2 / g of particles, and / or d) the particle size distribution d ₉₈ / d ₅₀ ≥ 2.0, more preferably > 2.5, and preferably > 2.5 to 3.0.

According to a further aspect of the present invention, there is provided an aqueous slurry obtained according to the process defined herein. The aqueous slurry includes a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a weight ratio [MCC / PCC] of from 99: 1 to 50:50.

According to a further aspect of the present invention there is provided a blend obtained by drying an aqueous slurry as defined herein. The blend includes surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) having a weight ratio [MCC / PCC] of 99: 1 to 50:50.

According to a further aspect of the present invention there is provided a process for the production of surface modified calcium carbonate-containing particles of an aqueous slurry as defined herein in paper, paper, paper, digital photographic paper, paint, coatings, adhesives, plastics, (MCC) and precipitated calcium carbonate containing particles (PCC), or the use of a blend as defined herein. In one embodiment, the blend of the surface modified calcium carbonate containing particles (MCC) and the precipitated calcium carbonate containing particles (PCC) of the aqueous slurry herein defined, or the blend defined herein, . In another embodiment, the quencher is present in an amount of 1-10% by weight, preferably 2-7% by weight, more preferably 3-5% by weight, based on the wet paint. In another embodiment, the surface of the dried paint or coating has a gloss at 85 ° measured according to DIN 67 530 of less than 10, preferably 0.5-9.5, more preferably 1-8, even more preferably Is in the range of 2-7.5.

According to a further aspect of the present invention there is provided a method of making a paper comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in an aqueous slurry as defined herein, or a blend as defined herein, , Digital photo paper, paint, coating, adhesive, plastic, or wastewater treatment.

In the following, this step is referred to in further detail of the present invention, particularly during the production of an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC). These technical details and embodiments are also understood to apply to the products of the present invention and their uses.

The term "slurry" or "suspension" in the sense of the present invention encompasses insoluble solids and water, and optionally further additives, and usually contains a large amount of solids, It is of high density.

The term "aqueous" slurry or suspension refers to a system, wherein the liquid phase comprises water, preferably water. However, the term does not exclude that the liquid phase of the aqueous suspension comprises a small amount of at least one water miscible organic solvent selected from the group comprising methanol, ethanol, acetone, acetonitrile, tetrahydrofuran and mixtures thereof. When the aqueous slurry comprises one or more water-miscible organic solvents, the liquid phase of the aqueous slurry may be present in the aqueous slurry in an amount of 0.1-40.0 wt%, preferably 0.1-30.0 wt%, more preferably 0.1-20.0 wt% By weight, most preferably 0.1-10.0% by weight, based on the total weight of the composition. For example, the liquid phase of the aqueous slurry is composed of water.

Where the term "comprising " is used in the specification and claims of the invention, it does not exclude other nonspecific elements of functional importance that are not important or important. For purposes of the present invention, the term " comprising "is considered to be a preferred embodiment of the term" comprising. If less than one group is defined to include at least a certain number of embodiments, it is also understood that this also preferably discloses a group consisting solely of such embodiments.

Whenever the words "comprising" or "having" are used, such terms are intended to be equivalent to the recited "comprises ".

Quot; a ", "an ", or" the "are used when referring to singular nouns, they include plural nouns unless specifically stated otherwise.

Terms such as " obtainable "or" regulatable "and" obtained "or" regulated "are interchangeable. It will be appreciated that, unless the context clearly dictates otherwise, the term "obtained " includes, by any means, a limited understanding by the term " obtained" Means that the term "obtained" does not imply that it should be obtained by the following sequence of steps.

The process of the present invention for producing an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) provides several advantages. First, the process of the present invention provides an aqueous suspension having a high solids content. Next, the process of the present invention provides higher productivity for lower energy and cost consumption and lower energy consumption for drying. In addition, a quencher, that is, a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) obtained by the process of the present invention may have the same quenching performance as a conventional quencher In comparison, it has even better performance.

Process step a)

In step a) of the process of the present invention, there is provided an aqueous slurry of surface modified calcium carbonate containing particles (MCC).

The aqueous surface modified calcium carbonate containing particle slurry preferably has a solids content of at least 5% by weight, preferably 5-60% by weight, more preferably 10-35% by weight, most preferably By weight is 15-30% by weight. However, lower solids content, such as less than 5% by weight or higher solids content, such as greater than 60% by weight, may also be used.

The water used to prepare the aqueous slurry of step a) is tap water, deionized water, process water or rainwater, or mixtures thereof. Preferably, the water used to prepare the aqueous slurry of step a) is tap water.

The aqueous slurry of step a) comprises surface modified calcium carbonate containing particles (MCC).

Preferably, the solids content of the aqueous slurry of step a) comprises surface modified calcium carbonate containing particles (MCC). More preferably, the solids content of the aqueous slurry of step a) consists of surface modified calcium carbonate containing particles (MCC).

In the context of the present invention, "surface modified calcium carbonate containing particles" (MCC) refers to particles of natural calcium carbonate and / or precipitated calcium carbonate obtained by reacting with acid and carbon dioxide, Formed and / or supplied from an external source. The acid treatment can be carried out with an acid having _a pK _a of 2.5 or less at 25 캜. If the pK _a at 25 DEG C is greater than or equal to zero, the acid is preferably selected from sulfuric acid, hydrochloric acid, or mixtures thereof. When the pK _a at 25 ° C is 0-2.5, the acid is preferably H ₂ SO ₃ , M ⁺ HSO ₄ ^- (M ⁺ is an alkali metal ion selected from the group comprising sodium and potassium), H ₃ PO ₄ , oxalic acid, or mixtures thereof.

In one embodiment, the surface modified calcium carbonate containing particles (MCC) is a substantially spherical surface modified calcium carbonate containing particle (bMCC).

In the context of the present invention, the term "substantially spherical" means that the appearance of spherical surface modified calcium carbonate containing particles is spherical or spherical.

Substantially spherical surface modified calcium carbonate containing particles (bMCC) can be obtained by the process described in EP 2 684 916 Al, which is incorporated herein by reference.

According to one embodiment, the amount of calcium carbonate in the surface-modified calcium carbonate-containing particles (MCC), preferably substantially spherical surface-modified calcium carbonate-containing particles (bMCC) ), Preferably at least 50% by weight, such as at least 60% by weight, preferably at least 50-100% by weight, based on the total dry weight of the substantially spherical, surface-modified calcium carbonate-containing particles (bMCC) 60-99.9 wt%, and most preferably 70-99.8 wt%. In one preferred embodiment, the amount of calcium carbonate in the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical, surface modified calcium carbonate containing particles (bMCC) is determined by the surface modified calcium carbonate containing particles ), Preferably 80-99.8 wt%, more preferably 90-99.8 wt%, and most preferably 96-99.8 wt%, based on the total dry weight of the substantially spherical surface-modified calcium carbonate-containing particles (bMCC) %to be.

The term "dry" calcium carbonate containing particles in the sense of the present invention include calcium carbonate having a total surface moisture content of less than 0.5% by weight, preferably less than 0.2% by weight, more preferably less than 0.1% by weight based on the total weight of the particles Quot; particle &quot;

The surface-modified calcium carbonate-containing particles (MCC), preferably substantially spherical surface-modified calcium carbonate-containing particles (bMCC) have a median grain diameter d _{50 as} measured by a molar masterizer of 4 μm to 100 μm, Preferably from 5 占 퐉 to 75 占 퐉, more preferably from 10 占 퐉 to 55 占 퐉, still more preferably from 15 占 퐉 to about 35 占 퐉.

Throughout the present invention, the "particle size" of calcium carbonate and other materials is described by its particle size distribution. The d _x value represents the diameter of the x weight percent of the particles having a diameter less than d _x . This means that the d ₂₀ value is 20% by weight smaller in all particles, and the d ₇₅ value means that 75% by weight of all particles have a smaller particle size. The d ₅₀ value is thus the weight median grain size, i.e. 50 wt% of all grains are larger and the remaining 50 wt% of the grain is smaller than this grain size. For purposes of the present invention, the particle size is specified as the weight median particle size d ₅₀ , unless otherwise indicated. Sedigraph, or sedimentation, can be used to determine the weight median particle size d ₅₀ value. For purposes of the present invention, the "particle size" of the surface-modified calcium carbonate is described as a volumetric particle size distribution. To determine the volumetric particle size distribution of the surface-modified calcium carbonate, such as volumetric center grain diameter (d ₅₀ ) or volumetric top-cut particle size (d ₉₈ ), a molybdenum masterizer 2000 can be used.

Additionally or alternatively, the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical surface modified calcium carbonate containing particles (bMCC), have a particle size distribution d ₉₈ / d ₅₀ <3, Is in the range of? 2.9, and more preferably in the range of 1.4-2.9. For example, the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical surface modified calcium carbonate containing particles (bMCC) have a particle size distribution d ₉₈ / d ₅₀ in the range of 1.4-2.8, Is in the range of 1.5-2.7, most preferably in the range of 1.6-2.6 or 1.7-2.5.

Additionally or alternatively, the surface modified calcium carbonate containing particles (MCC), preferably the substantially spherical surface modified calcium carbonate containing particles (bMCC), have a BET specific surface area measured using nitrogen and BET method ≥ 15 m ² / g, preferably ^{20 m 2 / g-200 m} 2 / g, more preferably ^{30 m 2 / g-150 m} 2 / g, even more preferably 40 m ² / g-100 m ² / g.

The "specific surface area (SSA)" of calcium carbonate in the sense of the present invention is defined as the surface area of calcium carbonate divided by the mass. As used herein, the specific surface area is determined by nitrogen gas adsorption using a BET isotherm and specified in m ² / g (ISO 9277: 2010).

Thus, in one embodiment, the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical surface modified calcium carbonate containing particles (bMCC)

a) the central grain diameter d _{50 as} measured by a molar masterizer is in the range of from 4 μm to 100 μm, preferably from 5 μm to 75 μm, more preferably from 10 μm to 55 μm, even more preferably from 15 μm 35 μm,

b) a BET specific surface area measured using nitrogen and BET method of ≥ 15 m ² / g, preferably 20 m ² / g-200 m ² / g, more preferably 30 m ² / g -150 m ² / g, even more preferably 40 m ² / g-100 m ² / g, or

c) the particle size distribution d ₉₈ / d ₅₀ is in the range of <3, more preferably? 2.9, and most preferably 1.4-2.9.

In an alternative embodiment, the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical, surface modified calcium carbonate containing particles (bMCC)

a) the central grain diameter d _{50 as} measured by a molar masterizer is in the range of from 4 μm to 100 μm, preferably from 5 μm to 75 μm, more preferably from 10 μm to 55 μm, even more preferably from 15 μm 35 μm,

b) a BET specific surface area measured using nitrogen and BET method of ≥ 15 m ² / g, preferably 20 m ² / g-200 m ² / g, more preferably 30 m ² / g -150 m ² a / g, still more preferably ^{40 m 2 / g-100 m} 2 / g,

c) the particle size distribution d ₉₈ / d ₅₀ is in the range of <3, more preferably? 2.9, and most preferably 1.4-2.9.

In one embodiment, the surface modified calcium carbonate containing particles (MCC), preferably substantially spherical surface modified calcium carbonate containing particles (bMCC) have a BET specific surface area of 30 m ² / g-90 m ² / g And the central grain diameter d ₅₀ is 10 μm-55 μm.

The aqueous slurry of surface modified calcium carbonate containing particles (MCC), preferably substantially spherical surface modified calcium carbonate containing particles (bMCC), may comprise one or more treating agents.

The term "one or more" treatment agents in the sense of the present invention means that the treatment agent comprises, and preferably consists of, one or more treatment agent (s).

In one embodiment of the present invention, the at least one treating agent comprises, and preferably consists of, one treating agent. Alternatively, the at least one treating agent comprises, preferably consists of, two or more treating agents. For example, the at least one treating agent comprises, and preferably consists of, two or three treating agents.

Preferably, the at least one treating agent comprises, and more preferably consists of, one treating agent.

In this case, the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC), preferably the substantially spherical surface-modified calcium carbonate-containing particles (bMCC), comprises at least one treatment agent, Preferably from 0.01% to 5% by weight, more preferably from 0.05% to 4% by weight, even more preferably from 0.2% to 4% by weight, based on the total dry weight of the composition, And at least one treating agent in an amount of 3% by weight.

One or more treating agents are usually added during the preparation of an aqueous slurry of surface modified calcium carbonate containing particles (MCC), preferably a substantially spherical surface modified calcium carbonate containing particles (bMCC).

Preferably, the aqueous slurry of surface modified calcium carbonate containing particles (MCC) comprises at least one treating agent when the surface modified calcium carbonate containing particle (MCC) is a substantially spherical surface modified calcium carbonate containing particle (bMCC) .

During the preparation of substantially spherical surface modified calcium carbonate containing particles (bMCC), one or more treatment agents are added to the calcium carbonate containing mineral particles (bMCC) to provide substantially spherical surface modified calcium carbonate containing particles upon further exposure to the chemical in the process As a coagulation agent. With reference to the preparation of substantially spherical surface-modified calcium carbonate-containing particles (bMCC), the process described in EP 2 684 916 A1, incorporated herein by reference, is mentioned.

The at least one treating agent is preferably selected from the group consisting of ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, aluminum sulfate, aluminum chloride, and / or its hydrated forms, silicates, A water-soluble non-ionic polymer, and combinations thereof.

In certain embodiments, the at least one treating agent is aluminum sulfate. In a further specific embodiment, the at least one treating agent is aluminum sulfate in hydrated form. In a preferred embodiment, the at least one treating agent is aluminum sulphate hexadecahydrate.

For example, the content of aluminum sulfate in the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC), preferably the substantially spherical surface-modified calcium carbonate-containing particles (bMCC) Preferably from about 0.1% to about 2% by weight, more preferably from about 0.2% to about 1% by weight, based on the weight of the composition. The content of aluminum sulphate is considered to be important, and accordingly the administration of hydrates requires corresponding adjustments to achieve the desired amount.

Process step b)

In step b) of the process of the present invention, an aqueous slurry of precipitated calcium carbonate-containing particles (PCC) is provided.

The precipitated calcium carbonate-containing particle aqueous slurry is preferably present in an amount of at least 5 wt%, preferably 5-60 wt%, more preferably 10-35 wt%, and most preferably 15-30 wt%, based on the total weight of the aqueous slurry Has a solids content of% by weight. In an alternative embodiment, the precipitated calcium carbonate containing particle aqueous slurry is preferably present in an amount of 5-60 wt%, more preferably 20-60 wt%, still more preferably 30-60 wt%, based on the total weight of the aqueous slurry %, And most preferably 40-60 wt%. However, lower solids content such as less than 5% by weight or higher solids content such as greater than 60% by weight may also be used.

In a preferred embodiment, the precipitated calcium carbonate containing particle aqueous slurry has a solids content of 40-60 wt%, e.g., 45-60 wt%, based on the total weight of the aqueous slurry. This high solids content is advantageous in obtaining an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) providing a high solids content. This is advantageous because it allows for less water to be removed and thus less energy and cost for the process, resulting in higher productivity and lower energy consumption for drying.

The water used to prepare the aqueous slurry of step b) is tap water, deionized water, process water or rainwater, or mixtures thereof. Preferably, the water used to prepare the aqueous slurry of step b) is tap water.

In the sense of the present invention, "precipitated calcium carbonate" (PCC) is a synthetic material and is generally obtained by precipitation after reaction of lime with carbon dioxide in an aqueous environment or by precipitation of calcium and carbonate ion sources in water. The PCC can be one or more of aragonite, vaterite, calcite or zeaxanthin mineralogical crystal forms. Preferably, the precipitated calcium carbonate-containing particles (PCC) are one of aragonite, vaterite, calcite or cubic triangular beads mineralogical crystal forms. More preferably, the precipitated calcium carbonate-containing particle (PCC) is a bivalent triangular-shaped mineralogical crystal form (sPCC).

Aragonite is usually needle-shaped, whereas vaterite is a hexagonal crystalline form. The knit site can form a triangular plane, prismatic, spherical, and fuzzy. PCC can be produced in a different way, for example by precipitation with carbon dioxide, lime soda method, or by the Solvay process, which is a by-product of ammonia products. The resulting PCC slurry can be mechanically dehydrated, dried and resuspended in water.

According to one embodiment, the amount of calcium carbonate in the precipitated calcium carbonate-containing particles (PCC) is at least 50 wt%, such as at least 60 wt%, preferably at least 50 wt%, based on the total dry weight of precipitated calcium carbonate- 100% by weight, more preferably 60-99.9% by weight, and most preferably 70-99.8% by weight. In a preferred embodiment, the amount of calcium carbonate in precipitated calcium carbonate-containing particles (PCC) is 80-99.8 wt%, more preferably 90-99.8 wt%, based on the total dry weight of precipitated calcium carbonate-containing particles (PCC) And most preferably 96-99.8 wt%.

The precipitated calcium carbonate-containing particles (PCC) preferably have a median grain diameter d ₅₀ measured by a sedimentation method of 0.1-100 μm, preferably 0.25-50 μm, more preferably 0.3-5 μm, Lt; / RTI &gt;

Preferably, the settling is a particle size distribution d ₉₈ / d comprises calcium carbonate ₅₀ value of the surface-modified particles (MCC), preferably comprises substantially surface-modified calcium carbonate of spherical particles (bMCC) comprises particles (PCC) calcium carbonate Which is beyond the corresponding value. For example, the precipitated calcium carbonate-containing particles (PCC) have a particle size distribution d ₉₈ / d ₅₀ in the range of? 3, more preferably? 3.2, and preferably 3.2-4.5. In one embodiment, the precipitated calcium carbonate containing particles (PCC) have a particle size distribution d ₉₈ / d _{50 ranging} from 3.5-4.2, such as 3.7-4.0.

Additionally or alternatively, the precipitated calcium carbonate containing particles (PCC) may have a BET specific surface area measured using nitrogen and BET method of 1-100 m ² / g, preferably 2-70 m ² / g, Is in the range of 3-50 m ² / g, in particular 4-30 m ² / g.

Thus, in one embodiment, the precipitated calcium carbonate-containing particles (PCC)

a) the central grain diameter d ₅₀ measured by the sedimentation method is 0.1-100 μm, preferably 0.25-50 μm, more preferably 0.3-5 μm and most preferably 0.4-3 μm;

b) a BET specific surface area measured using nitrogen and BET method of 1-100 m ² / g, preferably 2-70 m ² / g, more preferably 3-50 m ² / g, especially 4-30 m &lt; ² &gt; / g,

c) the particle size distribution d ₉₈ / d ₅₀ is in the range of ≥ 3, more preferably ≥ 3.2, preferably in the range of 3.2-4.5.

In an alternative embodiment, the precipitated calcium carbonate-containing particles (PCC)

a) the central grain diameter d ₅₀ measured by the sedimentation method is 0.1-100 μm, preferably 0.25-50 μm, more preferably 0.3-5 μm, most preferably 0.4-3 μm,

b) a BET specific surface area measured using nitrogen and BET method of 1-100 m ² / g, preferably 2-70 m ² / g, more preferably 3-50 m ² / g, especially 4-30 m &lt; ² &gt; / g, or

c) the particle size distribution d ₉₈ / d ₅₀ is in the range of ≥ 3, more preferably ≥ 3.2, preferably in the range of 3.2-4.5.

The aqueous slurry of the precipitated calcium carbonate-containing particles (PCC) of step b) is selected from the group consisting of ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, aluminum sulfate, aluminum chloride, and / , A water-soluble cationic polymer, a water-soluble amphoteric polymer, a water-soluble nonionic polymer, and combinations thereof. More preferably, the aqueous slurry of precipitated calcium carbonate-containing particles (PCC) of step b) does not comprise a treating agent.

Process step c)

In step c) of the process of the invention, the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC) of step a) is brought into contact with the aqueous slurry of the precipitated calcium carbonate-containing particles (PCC) of step b). In process step c), an aqueous slurry is obtained comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC).

Contacting the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC) of step a) with the aqueous slurry of precipitated calcium carbonate-containing particles (PCC) of step b) has the advantage of obtaining an aqueous slurry with a higher solids content Respectively. Thus, there is less water to be wasted and thus the process consumes less energy and less, thus providing higher productivity and lower energy consumption for drying.

Contact step c) may be accomplished by any conventional means known to those skilled in the art. Preferably, the contacting is carried out under mixing and / or homogenization and / or particle splitting conditions. Those skilled in the art will adjust these mixing and / or homogenization and / or particle partitioning conditions such as mixing rate, partitioning, and temperature according to process equipment.

For example, mixing and homogenization can be carried out using a plowshare mixer well known to those skilled in the art.

Process step c) is understood to be carried out by adding an aqueous slurry of the surface modified calcium carbonate-containing particles (MCC) of step a) to the aqueous slurry of precipitated calcium carbonate-containing particles (PCC) of step b). Alternatively, process step c) is carried out by adding an aqueous slurry of precipitated calcium carbonate-containing particles (PCC) of step b) to the aqueous slurry of surface-modified calcium carbonate-containing particles (MCC) of step a).

Preferably, process step c) is carried out by adding an aqueous slurry of precipitated calcium carbonate-containing particles (PCC) of step b) to the aqueous slurry of surface modified calcium carbonate-containing particles (MCC) of step a).

According to one embodiment, process step c) is carried out at a temperature in the range of 15 ° C to 80 ° C, preferably 20 ° C to 50 ° C, most preferably 20 ° C to 40 ° C.

An aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) is obtained in process step c).

The aqueous slurry obtained in step c) is preferably present in an amount of 5% by weight or more, preferably 5-40% by weight, more preferably 10-35% by weight, most preferably 15-40% by weight, And has a solids content of 30% by weight. In one embodiment, the aqueous slurry obtained in step c) preferably has a solids content of 20-30% by weight, such as 25-30% by weight, based on the total weight of the aqueous slurry. More solid contents of more than 40% by weight can also be obtained. This high solids content is advantageous because the process will provide higher productivity and lower energy consumption for drying, as less water is desired to be removed and thus the process consumes less energy and costs.

Particular advantages are obtained particularly when the blend contains surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a certain ratio.

Therefore, the blend is required to include surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a weight ratio [MCC / PCC] of 99: 1 to 50:50. Preferably, the blend comprises a surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a weight ratio of from 95: 5 to 65:35, more preferably from 90:10 to 70:30 [MCC / PCC].

The blend preferably includes surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) with a specific overall center grain diameter d ₅₀ . For example, the blend may have a median grain diameter d _{50 as} measured by a sedimentation method of 5 μm-100 μm, preferably 10 μm-75 μm, more preferably 15 μm-50 μm, more preferably 20 μm- Lt; / RTI &gt;

The particles in the blend may also have a specific particle size distribution. In particular, the blend may include particles having a particle size distribution d ₉₈ / d ₅₀ of ≥ 2.0, more preferably> 2.5, and preferably> 2.5-3.0.

Additionally or alternatively, the blend includes surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) to obtain a specific overall BET specific surface area. For example, the blend can have a BET specific surface area of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g, measured using nitrogen and BET -150 m &lt; ² &gt; / g, and even more preferably 30 m &lt; ² &gt; / g-100 m &lt; ² &gt; / g.

Thus, a blend comprising surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC)

a) the central grain diameter d ₅₀ measured by the sedimentation method is from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, even more preferably from 20 μm to 35 μm Particles, and / or

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, and / or

c) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,

And more preferably consists of the same.

In one embodiment, a blend comprising surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC)

a) particles having a median grain diameter d _{50 as} measured by a sedimentation method of 5-100 μm, preferably 10 μm-75 μm, more preferably 15 μm-50 μm, even more preferably 20 μm-35 μm , or

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, or

c) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,

And more preferably consists of the same.

In an alternative embodiment, a blend comprising a surface modified calcium carbonate containing particle (MCC) and a precipitated calcium carbonate containing particle (PCC)

a) the central grain diameter d ₅₀ measured by the sedimentation method is from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, even more preferably from 20 μm to 35 μm particle,

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, and

c) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,

And more preferably consists of the same.

If the aqueous slurry of surface modified calcium carbonate-containing particles (MCC) provided in step a) comprises more than one treatment agent, the aqueous slurry obtained in step c) preferably has a total dryness of the aqueous slurry obtained in step c) In an amount of up to 4% by weight, preferably in an amount of from 0.005% to 2.5% by weight, more preferably from 0.025% to 2% by weight, still more preferably from 0.1% to 1.5% It is understood that the above treatment agent is included.

Process step d)

In step d) of the process of the invention, the aqueous slurry obtained in step c) is dehydrated.

The term "dehydration " in the sense of the present invention means an increase in the solids content and a decrease in the water content obtained using thermal and / or mechanical methods.

The dehydration step d) can be carried out by any type of thermal and / or mechanical method known to those skilled in the art, which reduces the water content of the calcium carbonate-containing aqueous slurry. For example, the dehydration step d) can preferably be carried out by mechanical or thermal, such as filtration, centrifugation, sedimentation in a settling tank, evaporation, etc., preferably by jet or spray drying.

Preferably, the aqueous slurry comprising the blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) obtained in step c) is present in an amount of at least 15% by weight, based on the total weight of the aqueous slurry, Preferably 15-50 wt.%, More preferably 20-45 wt.%, And most preferably 20-40 wt.%.

It is understood that the dehydration step d) is carried out so that the resultant aqueous slurry has a solids content that is greater than the solids content of the aqueous slurry obtained in the contacting step c).

As a blend of the aqueous slurry obtained in step c), the blend obtained in step d) comprises a surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a specified weight ratio.

Thus, it is preferred that the blend obtained in step d) comprises surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a weight ratio [MCC / PCC] of from 99: 1 to 50:50 . Preferably, the blend obtained in step d) comprises a surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in a ratio of from 95: 5 to 65:35, more preferably from 90:10 to 70: 30 weight ratio [MCC / PCC].

The blend obtained in step d) preferably comprises a surface modified calcium carbonate containing particle (MCC) and a precipitated calcium carbonate containing particle (PCC) with a specific overall center grain diameter d ₅₀ . For example, the blend obtained in step d) has a median grain diameter d ₅₀ of 5 μm-100 μm, preferably 10 μm-75 μm, more preferably 15 μm-50 μm, More preferably 20 占 퐉 to 35 占 퐉.

The particles in the blend obtained in step d) may also have a specific particle size distribution. In particular, the blend may comprise particles having a particle size distribution d ₉₈ / d _{50 in the range} of ≥ 2.0, more preferably> 2.5, and preferably> 2.5-3.0.

Additionally or alternatively, the blend obtained in step d) comprises calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) that have been surface modified to have a specific overall BET specific surface area. For example, the blend obtained in step d) has a BET specific surface area of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, as measured using nitrogen and BET methods, Has a particle size of 20 m ² / g-150 m ² / g, even more preferably 30 m ² / g-100 m ² / g.

Thus, the blend comprising the surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) obtained in step d)

a) the central grain diameter d ₅₀ measured by the sedimentation method is from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, even more preferably from 20 μm to 35 μm Particles, and / or

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, and / or

c) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,

And more preferably consists of the same.

In one embodiment, the blend comprising the surface modified calcium carbonate containing particles (MCC) obtained in step d) and the precipitated calcium carbonate containing particles (PCC)

a) the central grain diameter d ₅₀ measured by the sedimentation method is from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, even more preferably from 20 μm to 35 μm Particle, or

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, or

c) particles preferably have a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5, preferably &gt; 2.5-3.0.

In an alternative embodiment, the blend comprising the surface modified calcium carbonate containing particles (MCC) obtained in step d) and precipitated calcium carbonate containing particles (PCC)

a) particles having a median grain diameter d _{50 as} measured by a sedimentation method of 5 μm-100 μm, preferably 10 μm-75 μm, more preferably 15 μm-50 μm, more preferably 20 μm-35 μm , And

b) a BET specific surface area measured using nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, and

c) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,

And more preferably consists of the same.

If the aqueous slurry of surface modified calcium carbonate-containing particles (MCC) provided in step a) comprises more than one treatment agent, the aqueous slurry obtained in step d) is preferably subjected to a total drying of the aqueous slurry obtained in step d) In an amount of up to 8% by weight, preferably from 0.01% to 5% by weight, more preferably from 0.05% to 4% by weight, even more preferably from 0.2% to 3% It is understood that the above treatment agent is included.

Process step d) is preferably carried out in the absence of a dispersant. Thus, the blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) preferably does not include a dispersant. More preferably, process steps a), b), c) and d) are carried out in the absence of a dispersant.

The process according to the invention may further comprise an optional drying step e). In the drying step, the aqueous slurry obtained in the dewatering step d) is dried to obtain a dried blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC).

The drying method applied to obtain a dry modified calcium carbonate-containing particle (MCC) and a precipitated calcium carbonate-containing particle (PCC) may be any type of drying method well known to those skilled in the art.

Thus, the solids content of the dry-blend of the surface-modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) obtained in the optional drying step e) is in the range of 20.0-99.0 wt%, based on the total weight of the blend , Preferably from 24.0 to 90.0% by weight. For example, the solids content of the dry-blend of surface-modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) obtained in the optional drying step e) is 20.0-60.0 wt% , Preferably from 24.0 to 50.0% by weight.

If the process comprises a drying step e), it is understood that the drying step is carried out so that the resultant blend has a solids content higher than the solids content of the aqueous slurry obtained in the dehydration step d).

With regard to the characteristics of the dry blend, the set features are discussed when discussing process steps c) and d).

Use of the invention

A blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) of the present invention or a blend of said surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) The aqueous slurry can be used in paper, foil, digital photo paper, paint, coatings, adhesives, plastics, or waste water treatment or waste water treatment.

In a preferred embodiment, the blend of the surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) of the present invention is used as a quencher in paints or coatings. As the extinction agent, the present applicant understands the agent as a preparation capable of scattering the introduced light away from the opposite angle. This means diffracting direct light that irradiates the substrate to induce scattering diffusion.

In particular, the quencher is present in an amount of 1-10% by weight, preferably 2-7% by weight, more preferably 3-5% by weight, based on the total weight of the paint or coating.

The paint or coating comprising a blend of the surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) of the present invention as the quenching agent in the amounts mentioned above in the amount of 85 DEG C The surface gloss of the dried film of the paint or coating is provided in the range of less than 10 gloss units (GU), preferably 0.5-9.5, more preferably 1-8, even more preferably 2-7.5, Which is very surprising.

A further advantage of the inventive surface modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) present in the amounts described above, in addition to the quenching effect of the dried film of the paint or coating, The surface of the painted coating or coating is smooth.

Thus, when used in paints and / or coatings, the blend of surface modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) of the present invention provides a quenching appearance while providing a tactile and smooth surface.

The following examples are intended to illustrate the invention without limiting its scope.

Example

How to measure

The following measurement methods were used to evaluate the parameters set forth in the description, examples and claims.

The BET specific surface area (SSA)

The samples were conditioned by heating at 250 DEG C for 30 minutes and then the specific surface area was measured with nitrogen through BET method according to ISO 9277 using Gemini V sold by MICROMERITICS ^TM . Prior to this measurement, the sample was filtered into a Buchner funnel, rinsed with deionized water and dried overnight in an oven at 90-100 &lt; 0 &gt; C. The dried cake was then completely worn out of the motor and the resulting powder was placed in a moisture measuring scale at 130 DEG C until a constant weight was reached.

Solid content of aqueous slurry

The slurry solids content (also referred to as "dry weight") was determined using a Moisture Analyzer HR73 available from Mettler-Toledo set to the following: temperature 120 ° C, automatic switch- 3, standard dry 5, 20 g slurry.

The particle size distribution (mass% particles having a diameter of < x) and the weight median diameter (d (mass% particles)) of the surface unreacted calcium carbonate- ₅₀ )

The weighted central grain diameter and grain diameter mass distribution of the particulate material, such as calcium carbonate, was determined through sedimentation, i.e., sedimentation aspect analysis in the gravimetric field. It was measured by Sadigraph TM 5120.

Methods and apparatus are known to those skilled in the art and are commonly used to determine the grain size of fillers and pigments. Measurements were carried out in a 0.1 wt% Na ₄ P ₂ O ₇ aqueous solution. Samples were dispersed using a high speed mixer and ultrasonic waves.

The center grain diameter of the spherical surface-modified calcium carbonate-containing minerals d ₅₀  And d ₉₈

The median grain diameter, d ₅₀ and d ₉₈ , of the spherical surface modified calcium carbonate containing minerals were determined using a Molburne MasterSizer 2000 laser diffraction system with specified RI 1.57 and iRI 0.005, molar application software 5.60. Measurements were performed on an aqueous dispersion. Samples were dispersed using a high-speed stirrer. In this regard, the values of d ₅₀ and d ₉₈ define the diameter, where the measured particles of 50 vol% or 98 vol% each have a diameter smaller than the d ₅₀ or d ₉₈ value, respectively.

Viscosity measurement

A. ICI Viscosity according to EN ISO 2884-1

ICI viscosities were measured using a cone and plate viscometer (Epprecht Instruments + Controls, Basel, Switzerland) at a shear rate of 10,000 1 / s and a temperature of (23 ± 0.2) ° C according to EN ISO 2884-1. The measured value after 15 s, which should be a constant, represents the measured viscosity of the sample.

B. Viscosity by Paar Physica M301 PP25 flowmeter

This measurement was carried out with a Parafiqa M301 PP25 flowmeter (Anton Paar GmbH, Austria) according to the following method:

Temperature: 23 ° C

Starting shear rate: 0.1 1 / s

Termination Shear rate: 100 1 / s, 10 units per 10 units. Algebraic variation of each measurement point, each measurement point taken after 5 seconds.

The measurement points are represented in decimal logarithmic fashion, and linear plots with negative slope are derived from these measurements. The x-axis of the graph represents the shear rate of the decimal logarithmic method and the y-axis represents the measured viscosity of Pa · s.

Gloss of coated surface

Surface gloss was measured at an angle listed in accordance with DIN 67 530 on a painted surface prepared with a coater spacing of 150 μm on a contrast card. The contrast card used was a Lenetta contrast card sold by Leneta, distributed by Novamart (STARPA, Switzerland), 3-BH foam, 7-5 / 8 x 11-3 / 8 size (194 x 289 mm). The luster was measured with a gloss measuring device of Byk Gardner (Gehrert, Germany). Gloss may be obtained by measuring at five different points on the card by means of a gloss measuring device, and the average value calculated by the device and guided to the display of the device.

Color value determination (Rx, Ry, Rz)

The color values Rx, Ry, and Rz were determined on the white and black fields of the Reneta Contrast Card and measured with a Spectraflas SF 450 X spectrophotometer from Datacolor (Montreux, France).

Contrast ratio of coated surface (opacity)

The contrast ratio value was determined according to ISO 2814 at a diffusion rate of 10 +/- 0.5 m &lt; ² &gt; / l.

The contrast ratio was calculated as described by the following equation:

At this time, Ry _black and Ry _white were obtained by measurement of color values.

Example

The following examples of the invention for the preparation of spherical MCC were prepared in a jacketed steel reactor equipped with a 10 m ³ batch size laminar mixing system. The solids content was adjusted to 20 wt% solids as shown in Table 1 below.

The process

a) providing at least one aqueous calcium carbonate containing mineral slurry;

b) providing at least one water soluble acid;

c) optionally, providing additional gaseous CO ₂ via an external path;

d) contacting said aqueous calcium carbonate containing mineral slurry of step a) with said acid of step b) and said CO ₂ generated and / or externally fed into the system of step c) under agitation conditions;

e) optionally, dewatering the aqueous slurry

.

Adding at least one water-soluble acid of step b), and contacting the aqueous calcium carbonate-containing mineral slurry of step a) with the acid and in situ generated and / or externally supplied CO ₂ of step b) Was carried out in a stirred reactor under agitation conditions such as essentially producing laminar flow.

The marbles used in the process of the present invention and presented as H90 in Table 1 below are commercially available from Applicants sold under the name Hydrocarb 90-ME 78%, which has a top cut d ₉₈ of 5 μm and a weight median particle size d ₅₀ Natural heavy marble of Molde, Norway, having a size of 0.7 μm (determined by Sadigraph), was provided in the form of a slurry having a solids content of 78% by weight and a viscosity of 400 mPas, based on the dry material of the slurry.

The mixing speed was adjusted to 48 rpm and the temperature was adjusted to 70 캜. Prior to administration of the 35 wt.% Solution of phosphoric acid added over 10-12 minutes, the treating agent aluminum hexadecahydrate was added to the calcium carbonate containing mineral slurry in an amount of about 0.3 wt.% At a time.

The reactants were mixed at the indicated mixing rates and times according to Table 1 below.

The particle size distributions (PSDs) of the E1 and E2 of the MCC synthesized using the molar masterizer and particle size distribution and the BET specific surface area SSA were measured and also the top cut d ₉₈ and the center grain diameter d of Examples E1 and E2 ₅₀ are shown in Table 2 below.

The slurry of Example E2 obtained after the reaction was mixed with a commercially available 54% by weight precipitated calcium carbonate slurry (Omya AG) and dried according to the following Table 3, wherein the precipitated calcium carbonate had a top cut d ₉₈ of 7 μm, A sediment of triangular mesoporous material with a median particle diameter d ₅₀ of 1.8 μm, a particle size of 60% by weight measured by Sadigraph 5120 of <2 μm and a luminance Ry (C / 2 °, DIN 53163) of 97% Calcium carbonate (sPPC). In addition, the slurry E2 was first dried and then blended with the already mentioned dry triangles PCCs at different ratios as shown in Table 3 below.

Dry blends of MCC and sPCC and dried samples obtained in dried wet blends were tested in paint. To this end, R1, DB1 to DB3 and WBd1 were mixed in the formulation and compared with a quencher, such as diatomaceous earth (R2-celite 281) used in this area. The dosage level of all quenchers was 7 wt%. Such formulations may additionally comprise conventional additives such as antifoaming agents, dispersants, sodium hydroxide fungicides, bactericides, titanium dioxide (rutile), talc, fillers, pigments, thickeners, plasticizers, viscosity modifiers, water and others known to those skilled in the art. Table 4 below provides the composition of the test paint.

Fillers and pigments were replaced on a volumetric basis, i. E. By the same pigment volume concentration (PVC). The paint was tested for dry opacity (ISO 2814), white Ry (DIN 53145) and gloss (DIN 67530) (gloss at 85 °). The ingredients and functionality of the materials for basic test paints, which are commercially available products known to those skilled in the art, are set forth in Table 5 below.

The performance of the tested peptides is summarized in Table 6, where DB1, DB2, DB3, DB4 and DB5 refer to the paint comparison obtained from the dry blend, while R1 (100% MCC) and R2 (Celite 281 from Imerys , Calcined diatomaceous earth) refers to a paint reference example. WBd1 refers to a paint embodiment comprising a blend obtained by the process of the present invention.

As can be seen from the results in Table 6 above, the example (WBd1) according to the present invention exhibits a quenching effect similar to that of the conventional quenching agent of the prior art R2, which is superior to the dry blend of DB3 of the same MCC / sPCC ratio.

Accordingly, the present invention provides an alternative quencher based on a wet-blend of surface modified calcium carbonate and precipitated calcium carbonate, which comprises the same proportions of surface-modified calcium carbonate and precipitated calcium carbonate It is possible to provide a quenching effect superior to the dry blend on one side and improve the production and cost efficiency of the subsequently dried wet blend. This improved production and cost efficiency was achieved by blending 20 wt% MCC slurry with 54 wt% sPCC slurry with 6.21 parts of MCC and 1 part of sPCC with a solids content of 4.7 and 24.7 wt% Lt; RTI ID = 0.0 &gt; MCC / sPCC &lt; / RTI &gt; Thus, in order to obtain a dry blend of the dry starting material with a 70/30 ratio of MCC / PCC, there is more water to be removed than wet blending and drying, and consequently less water to be removed, And less production costs.

The MCC / PCC blends of the present invention can be used in paper and paper coatings, foil paper, digital photographic paper, paints, coatings, adhesives, plastics, or as wastewater treatment agents.

Claims (15)

A method of making an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC)
a) providing an aqueous slurry of surface modified calcium carbonate containing particles (MCC)
b) providing an aqueous slurry of precipitated calcium carbonate containing particles (PCC)
c) The aqueous slurry of said surface modified calcium carbonate containing particles (MCC) of step a) to obtain an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) With an aqueous slurry of the precipitated calcium carbonate-containing particles (PCC) of step b), and
d) dewatering the aqueous slurry obtained in step c) to obtain an aqueous slurry comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC)
Wherein the blend comprises surface-modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) in a weight ratio [MCC / PCC] of 99: 1 to 50:50. The process according to claim 1, wherein the surface-modified calcium carbonate-containing particles (MCC) in the aqueous slurry of step a) is a substantially spherical surface-modified calcium carbonate-containing particle (bMCC). 3. The process according to claim 1 or 2, wherein the surface modified calcium carbonate containing particles (MCC) in the aqueous slurry of step a)
a) the central grain diameter d ₅₀ measured by a Malvern Mastersizer is from 4 μm to 100 μm, preferably from 5 μm to 75 μm, more preferably from 10 μm to 55 μm, 15 [mu] m to about 35 [mu] m and /
b) a BET specific surface area measured using nitrogen and BET method of ≥ 15 m ² / g, preferably 20 m ² / g-200 m ² / g, more preferably 30 m ² / g -150 m ² / g, even more preferably 40 m ² / g-100 m ² / g and /
c) the particle size distribution d ₉₈ / d ₅₀ is in the range of <3, more preferably ≤ 2.9, and preferably 1.4-2.9. 4. A process according to any one of claims 1 to 3 wherein the aqueous slurry of surface modified calcium carbonate containing particles (MCC) of step a) is present in an amount of up to 8% by weight, based on the total dry weight of the aqueous slurry, By weight, preferably from 0.01% to 5% by weight, more preferably from 0.05% to 4% by weight, and even more preferably from 0.2% to 3% by weight. 5. The method of claim 4, wherein the at least one treating agent is selected from the group consisting of ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, aluminum sulfate, aluminum chloride, and / or its hydrated forms, silicates, A water-soluble amphoteric polymer, a water-soluble nonionic polymer, and combinations thereof. 6. A process according to any one of claims 1 to 5, wherein the precipitated calcium carbonate-containing particles (PCC) in the aqueous slurry of step b)
a) the central grain diameter d ₅₀ measured by the sedimentation method is 0.1-100 μm, preferably 0.25-50 μm, more preferably 0.3-5 μm, most preferably 0.4-3 μm and /
b) a BET specific surface area measured using nitrogen and BET method of 1-100 m ² / g, preferably 2-70 m ² / g, more preferably 3-50 m ² / g, especially 4-30 m &lt; ² &gt; / g and /
c) the particle size distribution d ₉₈ / d ₅₀ is in the range of ≥ 3, more preferably ≥ 3.2, preferably in the range of 3.2-4.5. 7. The method according to any one of claims 1 to 6,
a) the aqueous slurry of the surface-modified calcium carbonate-containing particles (MCC) of step a) and / or the precipitated calcium carbonate-containing particles (PCC) of step b) is present in an amount of not less than 5% by weight, based on the total weight of the aqueous slurry , Preferably from 5 to 60 wt.%, More preferably from 10 to 35 wt.%, Most preferably from 15 to 30 wt.%,
b) The aqueous slurry obtained in step c) is present in an amount of 5% by weight or more, preferably 5-40% by weight, more preferably 10-35% by weight, most preferably 15-30% by weight, Having a solids content of% by weight,
c) The aqueous slurry obtained in step d) comprises at least 15% by weight, preferably 15-50% by weight, more preferably 20-45% by weight, most preferably 20-40% by weight, based on the total weight of the aqueous slurry % &Lt; / RTI &gt; solids. 8. The blend of any one of claims 1 to 7, wherein the blend
a) a surface modified calcium carbonate containing particle (MCC) and a precipitated calcium carbonate containing particle (PCC) in a weight ratio [MCC / PCC] of 95: 5 to 65:35, preferably 90:10 to 70:30; and /or
b) the central grain diameter d ₅₀ measured by the sedimentation method is from 5 μm to 100 μm, preferably from 10 μm to 75 μm, more preferably from 15 μm to 50 μm, even more preferably from 20 μm to 35 μm Particles, and / or
c) a BET specific surface area measured by nitrogen and BET method of ≥ 5 m ² / g, preferably 10 m ² / g-200 m ² / g, more preferably 20 m ² / g -150 m ² / g, even more preferably 30 m ² / g-100 m ² / g, and / or
d) particles having a particle size distribution d ₉₈ / d _{50 in the range} of > = 2.0, more preferably > 2.5,
&Lt; / RTI &gt; A surface modified calcium carbonate-containing particle (MCC) and a precipitated calcium carbonate-containing particle (PCC) of 99: 1 to 50:50 weight ratio [MCC / PCC] obtained according to any one of claims 1 to 8, &Lt; / RTI &gt; A blend of surface modified calcium carbonate-containing particles (MCC) and precipitated calcium carbonate-containing particles (PCC) in a weight ratio [MCC / PCC] of 99: 1 to 50:50 obtained by drying the aqueous slurry of claim 9. The surface-modified calcium carbonate-containing particles (MCC) and the precipitated calcium carbonate-containing particles (B) in the aqueous slurry of claim 9 in a paper, a paper coating, a bamboo paper, a digital photographic paper, a paint, a coating, an adhesive, PCC) or the blend of claim 10. 12. Use according to claim 11 as a quencher in paints and coatings. 13. Use according to claim 12, wherein the quencher is present in an amount of 1-10% by weight, preferably 2-7% by weight, more preferably 3-5% by weight, based on the wet paint. The coating of claim 13, wherein the surface of the dried paint or coating has a gloss at 85 ° measured in accordance with DIN 67 530 in the range of less than 10, preferably 0.5-9.5, more preferably 1-8, Preferably 2-7.5. A paper, foil, digital photographic paper, paint, coating, adhesive (s) comprising a blend of surface modified calcium carbonate containing particles (MCC) and precipitated calcium carbonate containing particles (PCC) in the aqueous slurry of claim 9, , Plastic, or wastewater treatment.